Flask redirect success and return html but page not loading

The redirect request is success, and returns the new HTML file, but the page is not loading, I think maybe it is because js issues.

function in flask is:

@app.route('/api/ocr', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        file = request.files['file']
        with open(file.filename, "wb+") as fw:
            fw.write(file.read())
            fw.seek(0, 0)
            data = {'file': fw}
            response = requests.request("POST", "https://freeocrapi.com/api", files=data)
            parsed_text = re.search(r'"text": "(.*?)"', response.text).group(1)
        return redirect(url_for('invocation',parsed_text=parsed_text))
    return render_template("ocr.html")

javascript is:

    <script type="text/javascript">
      async function SavePhoto(inp) {
        let formData = new FormData();
        let file = inp.files[0];

        formData.append("file", file);
        formData.append("name", file.name);
        console.log(file);
        const ctrl = new AbortController(); // timeout
        setTimeout(() => ctrl.abort(), 5000);

        try {
          let r = await fetch("http://127.0.0.1:5000/api/ocr", {
            method: "POST",
            body: formData,
            signal: ctrl.signal,
          });
          console.log("HTTP response code:", r.status);
        } catch (e) {
          console.log("Huston we have problem...:", e);
        }
      }
    </script>